Automatic train-stop.



H. G. SEDGWICK AUTOMATIC TRAIN STOP. APPLICATION FILED OCT. 24. 1908. RENEWED 0U. 14. 1916.

1,226,915. Patented May 22,1917.

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AUTO MATIC TRAIN STOP. APPLICATION FILED OCT- 24. I908. RENEWED OCT. 14. I916.

1,226,91 5. Patented May 22, 1917.

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IIIIIIIIIII/ Witumozo H. G. SEDGWICK.

AUTOMATIC TRAIN STOP. APPLICATION FILED OCT-24,1908. RENEWED OCT. 14.4916.

1,226,91 5. Patented May 22, 1917.

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" HO/n T/ifll/V PIPE If 6 Wm 7'0 STEAM Isl/PHI] 1 W 01? PRESSURE 4 I I: x I d J I Z0" L l m QMAMYYWOTI witnum I I 7 I a IGW W UNITED STATES PATENT omnon HIBAM G. SEDG'WICK, OF MILL VALLEY, CALIFORNIA, ASSIGNOR TO THE NATIONAL SAFETY APPLIANCE COMPANY, A CORPORATION OF CALIFORNIA.

AUTOMATIC TRAIN-STOP.

Specification of Letters Patent.

Patented May 22, 1917,

Application filed October 24, 1908, Serial No. 459,358. Renewed October 14, 1916. Serial No. 125,704.

To all whom it may concern:

Be it known that I, HIRAM' G. Snocwron, a citizen of the United States of America, and a resident of Mill Valley, in the county of Marin and State of California, have invented certain new and useful Improvements in Automatic Train-Stops, of which the following is a full and .clear specification. r v

This invention relates to automatic vent valves and to a magnetic means for controllingthe action of the same in that class of automatic railway stops in which the trainpipe is automatically vented to apply the brakes when a normally-closed circuit on thelocomotive is opened by suitable means on the roadbed.

The object of the present improvements is to increase vthe reliability bf the apparatus, rendering it practicallyimpossible to permit any of the parts tobecome deranged or inoperative without that fact being made known to the train crew by the application of the'brakes, whereby it will be impossible for the train to proceed until this automatic stopping device is in perfect working order, as more fully hereinafter set forth.

In the accompanying drawings-- Figure 1' is a vertical sectional view of the magnetic mechanism for actuating the pilot valve controlling the action of the vent valve, parts of the device being shown in side elevation and the wiring being shown in diagram;

Fig. 2 is a; side elevation, partly in section, showing the weight down and the pilot valve actuated, and also showing a device for preventing the rebounding of the weight;

Figs. 3, 4 and \5sh0W similar views of modified forms of the type of device shown in Figs. 1 and 2;

Fig. 6 is a similar view of another modification. v

Referring to Fig, I, a designates a portion of the train-pipe which communicates with a cylinder 5 through one head thereof, in which cylinder is mounted a free piston 0 which normally, by its own weight, with or without the assistance ofa spring d, tends to move toward the head of the cylinderthrough which the train-pipe enters thus normally closing the exhaust port 6 in the side of the cylinden This exhaust port consists preferably of a series of holes increasing in diameter in a direction away from the train-pipe port, this arrangement being preferred as it insures the gradual application of the brakes.

The piston c is held in a closed position under normal conditions by fluid pressure from a suitable source, namely from asteam space of the boileror from a pressure reservoir, this pressure being communicated to a chamber above the piston bymeans' of a pipe f and ports g, h and 2', the port 71 being in a pilot valve j slidably mounted in a suitable cylinder .and the ports 9 and it being in the adjacent portions ofthe casing of the pilot valve and the cylinder a. The spring is normally holds up the pilot valve or piston j in normal register with the ports 9 and h, a stop-collar Z being provided on the stem m of this valve for limiting its upward movement and said stem being extended upwardly through the head of the pilot valve cylinder.

Ina frame or guide a above the pilot valve is mounted a weight 0 which is sufiiciently heavy when dropped to force the pilot valve down against the action of its spring k and thus close the inlet port 9 and put port it in communication .with an annular exhaust port 10 around the pilot valve and an escape port 9 in the pilot valve casingand thus relieve the piston c of normal downward pressure and permit the trainpipe pressure to force it upwardly and open' the vent port 6 and thus apply the brakes The weight 0 is supported upon the inner ends of a pair of levers r pivoted in the guide frame and provided at their outer ends with armatures s which are normally attracted to normally energized magents t included by normally-closed circuits or with a suitable battery o preferably of the low tension bluestone type. The wires w constitute a partial shunt-circuit connected with the circuits u and havingas its terminals the contact-brush a and one of the axles of the locomotive, or other suitable current collectors or contacts adapted to contact with devices on the roadbed and complete this partial a shunt-circuit when a danger point on .the' roadbed is reached.

It will be observed that when the shuntcircuit '20 is completed. the current from battery '2) willbe shunted from the magnets, thus releasing the armatures s and allowing the weight td fall and open the pilot valve in .the manner set forth. j The sudden dropping. of the weight gives the pilot valve a sudden hannnerdike blow and thus serves to dislodge it it"it be stuck. An advantage of breaking of spring in the brakes will be applied. The brakes ,will be applied also it for any reason the fluid pressure above the I piston 0 is allowed toleak out sufficiently to permit the train-pipe pressure to force piston 0- upwardly. I

In Fig. 2 the sides of the guide-bars are provided with teetha" which are adapted to normally engage spring-actuated pawls b when the weight is down and thus prevent rebound. These pawls are connected with theweight-lifting rod 0' in such manner that when the weight is lifted these pawls will be automatically withdrawn from engagement with the teeth a. g

In Fig. 6 the cylinders and magnet are arranged vertically and the arm 0 is adapted to be swung upwardly by a weight, this weight being preferably formed integral with the armature s. In this form of device the restoring spring is may not be needed as gravity may be relied upon to restore the pilot valve In this form of de-' vice the spring d is desirable in order to keep the main piston valve 0 normally raised.

The form of apparat s shown in Fig. 3 is substantially the same as that shown in Fig. 1, except as follows r The pilot valve is'arranged on top of the main valve and its port l is normally closed, the valve being normally held up by the spring is. The pipe a connects to the train-pipe and the pilot valve normally closes it, but when the pilot valve is de-' pressed by the weight the annular port Z will put this pipe a into communication with a port 1) leading into the top of the cylinder of the, main or vent valve. This vent valve is normally held up by a spring 1 and thus normally closes the vent port e. When this vent valve is depressed by; the

pressure of the train-pipe down upon its upper side a port 0 in the valve will be put into connnunicatimi' with the vent port a and the l rakeswill be ap )lied.

In the form shown in Fig. :3 the port Z is elongated so as to have connnunication vent valve ,,wl1ereby it is possible to obtain an emergency application of the brakes or a slow or quickservic'e application of the brakes. Th'is'is accomplished as is obvious by the amount of overlap of the ports Z and 6, it being obvious that the greater the overlap thequicker will be the opening of the vent valve. With this form of device the port 6 may be a graduated one, as shown, or it .1-nay be a single opening or slot.

. In the form of device shown in Fig. 4: the annular port Z is replaced by a short port Z. opening out through the bottom of the valve, and the pipe a is replaced by a pipe f leading from the boiler. The vent valve is provided with a. wide annular port 6 which is at all times in communication with the train-pipe a-tapped through the side of the cylinder. In this form of the device,

when the vent valve is depressed by steam pressure, the port e will place the trainpipe in communication with the vent port 6, as is obvious.

It will be observed that in all forms the armature, whether it be a weight or not, will, when released, move far enough away from the magnet to be out of its active field so that thedevice cannot be automatically reset but. must be manually re-set.

Having thus fully described my invention,

what I claim as new and desire to secure by Letters Patent, is

1. In an automatic train stop, a vent valve and means for opening the same, magnetic devices normally holding said opening means inoperative, these devices including a closed circuit and said opening means embodying, a pilot valve, a weight which when freed will deliver an impact or hammer blow to said pilot valve and thus operate it, and devices under control of the magnetic devices for holding said weight out of action.

2. In a train stop", the combination with a fluid pressure airbrake system, a vent valve for the train pipe and means for normally holding it closed, and a fluid pressure pilot valve for actuating said vent valve, said pilot valve being provided with a projecting stem, and means for opening'the pilot valve In testimony whereof I hereunto afiix my by impact or hammer blow, said means consignature in the presence of two witnesses 10 sisting of a weight tending to (inolve toward this 8th day of October, 1908.

t e stem of said pilot va ve, an e ectromagnetic means for holding the weight against HIRAM SEDGW'IGK' said tendency and for releasing the weight Witnesses:

to permit it to strike the stem with a ham- S. H. RoBER'rs,

mer blow. I J. H. ARMISTEAD. 

